SU-F-I-28: CTQA: Clinically Relevant Testing




to develop a CTQA program centered on Quantitative Image Quality and Patient Dose.


Image Noise was selected as the Image Quality metric, defined as the standard deviation of an ROI, drawn within designated areas on clinical images of routine brain and abdomen scans. Patient Dose was defined as the dose to the particular “slice” used for the noise measurement. Baseline performance values were acquired for the scans, for each CT scanner in the system. For abdomens, the population was divided into four size categories. Upon completion of establishing baseline performance, quarterly sampling of each scanner population was initiated. Values outside the expected range are investigated, and, if indicated, interventions are made, and the results monitored.


In the two years since its inception, we have discovered numerous situations which required intervention, i.e. protocol adjustments to regain baseline performance. During the same period of time, no deficiencies were reported on any annual CT QA inspections.


Monitoring Image Noise and Patient Dose for consistency are effective QA tools. They are easy to implement and imbue clinical relevance to the QA program.